This is about a Model A with a Model B motor. The motor has good compression, has been rebuilt, and is in good shape, but it is not running. It will start and run for a few seconds and then quit. The fuel line has been checked, the carburetor replaced twice, the ignition system replaced twice, the voltage checked, and the exhaust system checked for blockage. The mechanic who rebuilt the motor can't figure it out.

You said Model B,....that means fuel pump, right? Or are you feeding the carburetor via gravity feed as in Model A? If you are using the Model B fuel pump, maybe it'll run better with gravity feed like a Model A which might indicate a fuel pump problem,.....just a thought,.....harold

I had a similar problem with a Model A. The condenser would fail once it warmed up. I had replaced it but the new one was defective. Just a thought. Also, fuel delivery... line blockage will allow engine to run for a few moments. The engine dies, then by the time you check the carb, it has re-filled. This happened with my '13 Speedster. Coating the gas tank fixed that.

A little OT: my Dad had a Model B pickup, probably bought in the 1930s. The motor went bad, so it was replaced with a Model A motor. He sold it with his washing machine business in summer of 1947. This was in Ashland, Oregon.

Has anybody seen a red Model B pickup with A engine, and a Maytag painted on the doors?

All the ignition and fuel system components were changed out at least once. No change when run with gallon can gravity feed.

I suspect that a new component, such as a condenser or carburetor, is bad. Most likely something in the carburetor. The owner said that it ran longer when choked, which indicates to me a problem with the float valve. He did everything in the book to try and get it running.

Anyway, it is mute point now as it has been sold to someone else. It was on Craigs List. A nice Fordor sedan for about half the going price. In Iowa. I am currently in southern California, so it would have been expensive to go see it. I am sure I could have fixed it and had a nice A for half price. Oh well.

The fact that it will run for only a few seconds makes it less likely a fuel-delivery problem. If the line is clogged, the bowl will fill slowly, but on a full bowl the engine will run a while.

More likely ignition is being shorted out by wiring or the distributor internals being jiggled by engine vibration. Does it have the factory switch wire to the distributor? If so, does it have the big grommet on it at the wiring box on the dash? If not (they are often left off because repos don't fit), then the shield on the switch-wire is bumping against a connector stud in the wiring box and shorting out your ignition when the engine starts vibrating.